Abstract: A node (200) is provided for use in a LiFi system (100) to provide LiFi signals to an endpoint device (130). The node (200) comprises a visible light source (220) for emitting modulated visible light and non-modulated visible light to provide illumination, and an infrared light source (210) for emitting modulated infrared light. The node (200) is configured to output a LiFi signal at a first one or more frequencies via the infrared light source (210) for reception by said endpoint device (130). In response to receiving input to provide illumination, the node (200) turns on the visible light source (220) to provide said illumination and automatically transfers an output of the LiFi signal from the infrared light source (210) to the visible light source (220) by outputting the LiFi signal at said first one or more frequencies via the visible light source (220) for reception by said endpoint device (130), and turning off the infrared light source (210).

Abstract: The disclosure provides a method and a system for adjusting an irradiation angle of a lamp and a lamp with adjustable irradiation angle. The lamp includes a plurality of infrared receivers and a driving motor. The method comprises: receiving an infrared signal from a remote controller via the plurality of infrared receivers; determining an irradiation angle adjustment value of the lamp based on a plurality of infrared signal intensity values of the plurality of infrared receivers; adjusting an irradiation angle of the lamp via the driving motor based on the irradiation angle adjustment value. In the technical scheme provided by the example of the disclosure, when the irradiation angle of the lamp needs to be adjusted, the irradiation angle of the lamp is controlled only by operating the remote controller.

Abstract: A communication system that includes a cloud server that obtains first sensor data associated with a defined indoor area and second sensor data associated with each of a plurality of optical nodes in defined indoor area. The plurality of optical nodes includes a master communication device, a plurality of optical routing devices, and one or more service communication devices. The cloud server further obtains location coordinates of each of the plurality of optical nodes. The cloud server then causes the master communication device to form a laser beam-based wireless communication network in the defined indoor area. A free-space optical backhaul is constructed by establishing a point-to-point free-space laser link between each pair of optical nodes of the plurality of optical nodes and a RF supervisory link is established between each pair of optical nodes of the plurality of optical nodes for a network monitoring and control function.

Abstract: Systems and methods are described for transmitting information optically. For instance, a system may include an optical source configured to generate a beam of light. The system may include at least one modulator configured to encode data on the beam of light to produce an encoded beam of light/encoded plurality of pulses. The system may include a spectrally-equalizing amplifier configured to receive the encoded beam of light/encoded plurality of pulses from the at least one modulator and both amplify and filter the encoded beam of light/encoded plurality of pulses to produce a filtered beam of light/filtered plurality of pulses, thereby spectrally equalizing a gain applied to the encoded beam of light. In some cases, the system may slice the beam of slight, to ensure a detector has impulsive detection. In some cases, the system may include a temperature controller to shift a distribution curve of wavelengths of the optical source.

Abstract: A plurality of digital processors may be used to adjust phases in a plurality of phase modulators. The plurality of digital processors may receive a periodic pulse, or heartbeat signal, from a synchronization controller in order to control the digital processors. The synchronization controller may output an additional signal used to determine and to control the phase of the signals output from the plurality of phase modulators.

Abstract: A method for calibrating a radio transceiver begins by injecting a low-frequency tone at a transmit power amplifier input of the radio transceiver, where the low frequency tone is at least an order of magnitude lower than the operating frequency of a local oscillator coupled to the transmitter input. The method continues by upconverting the low-frequency tone to produce a plurality of tones at a transmit power amplifier output and then determining which tone of the plurality of tones is a local oscillator feedthrough tone associated with a transmit power amplifier output and which tone of the plurality of tones is representative of an in-phase and quadrature (I/Q) imbalance associated with the transmit power amplifier output.

Abstract: A system comprises quantum control interconnect circuitry configured to receive a plurality of fixed-frequency signals, a variable-frequency signal, a quantum control pulse, a quantum element readout pulse, and a quantum element return pulse. The circuitry is operable to upconvert the quantum control pulse using the fixed-frequency signals. The circuitry is operable to upconvert the readout pulse using the variable-frequency signal. The circuitry is operable to downconvert the return pulse using the variable-frequency signal.

Abstract: A system and method are provided herein for communicating with and controlling various devices using visible light communication (VLC). According to one embodiment, a method is provided for extending a communication range of a VLC system comprising a plurality of controlled devices and a remote-control device. Such a method may include, for example, transmitting a communication message from a remote-control device to a first controlled device located within range of the remote-control device, wherein the communication message is transmitted through free space using visible light, and extending the communication range of the VLC system to a second controlled device, which is located outside of the range of the remote-control device, by using the first controlled device to retransmit the communication message through free space using visible light to the second controlled device.

Abstract: A communication system that includes a cloud server that obtains first sensor data associated with a defined indoor area and second sensor data associated with each of a plurality of optical nodes in defined indoor area. The plurality of optical nodes includes a master communication device, a plurality of optical routing devices, and one or more service communication devices. The cloud server further obtains location coordinates of each of the plurality of optical nodes. The cloud server then causes the master communication device to form a laser beam-based wireless communication network in the defined indoor area. A free-space optical backhaul is constructed by establishing a point-to-point free-space laser link between each pair of optical nodes of the plurality of optical nodes and a RF supervisory link is established between each pair of optical nodes of the plurality of optical nodes for a network monitoring and control function.

Abstract: An integrated chip packaging for a LIDAR sensor mounted to a vehicle includes a laser assembly configured to output a beam, an optical amplifier array chip configured to amplify a beam, and a transceiver chip coupled to the laser assembly and the optical amplifier array chip. The transceiver chip may be configured to emit the beam with reference to a first surface of the transceiver chip through an optical window and receive a reflected beam from a target through the optical window. The integrated chip packaging for the LIDAR sensor defines the configuration of optical components for providing a path for the optical signal to travel in and out of the LIDAR sensor and dissipating the heat generated by the optical components for improved performance.

Abstract: A system includes a first unit configured to generate a plurality of modulator control signals, and a processor unit. The processor unit includes: a light source or port configured to provide a plurality of light outputs, and a first set of optical modulators coupled to the light source or port and the first unit. The optical modulators in the first set are configured to generate an optical input vector by modulating the plurality of light outputs provided by the light source or port based on digital input values corresponding to a first set of modulator control signals in the plurality of modulator control signals, the optical input vector comprising a plurality of optical signals. The processor unit also includes a matrix multiplication unit that includes a second set of optical modulators.

Abstract: A communication system that includes a cloud server that obtains first sensor data associated with a defined indoor area and second sensor data associated with each of a plurality of optical nodes in defined indoor area. The plurality of optical nodes includes a master communication device, a plurality of optical routing devices, and one or more service communication devices. The cloud server further obtains location coordinates of each of the plurality of optical nodes. The cloud server then causes the master communication device to form a laser beam-based wireless communication network in the defined indoor area. A free-space optical backhaul is constructed by establishing a point-to-point free-space laser link between each pair of optical nodes of the plurality of optical nodes and a RF supervisory link is established between each pair of optical nodes of the plurality of optical nodes for a network monitoring and control function.

Abstract: A lighting fixture having a light source, a light sensor, a communication interface, and circuitry is described. In addition to controlling the light source, the circuitry is adapted to monitor for a light signal provided from a handheld device via the light sensor; upon receiving the light signal, measure a signal level associated with the light signal; and effect transmission of the signal level to the handheld device via the communication interface. In one embodiment, the circuitry is further configured to receive an instruction to monitor for the light signal from the handheld device via the communication interface such that the circuitry begins monitoring for the light signal upon receiving the instruction.

Abstract: A fiber-based master optical power amplifier (MOPA) is configured to utilize a pump source that operates in pulse mode with the arrival time of the pump pulses coordinated with the arrival time of the input pulses. The width of the pump pulses is also controlled, thus providing a mechanism for controlling both the amount of pump energy injected into the fiber amplifier, as well as the overlap in time between the pump pulse and the seed pulse. As the pulse repetition interval (PRI) of the input seed pulse changes, the timing of the pump pulses and their width are also changed so that a “constant gain” environment is created within the amplifying medium, providing an essentially constant energy output pulse, regardless of differences in ASE generated during different PRIs.

Abstract: A communication system that includes a master communication device at a first location in a defined indoor area, a service communication device at a second location in the defined indoor area, and passive optical routing devices at a plurality of locations in the defined indoor area. The master communication device obtains a first signal from a data source or a modem and directs a first laser beam carrying the first signal in a downstream path to a service communication device directly or via the plurality of passive optical routing devices based on defined connectivity criterions. The service communication device demodulates the first signal from the first laser beam, distributes one or more wireless signals to end-user devices, and further obtains one or more second signals from end-user devices and re-transmits obtained signals over second laser beam in upstream path to master communication device directly or via the passive optical routing devices.

Abstract: Systems and methods are described for transmitting information optically. For instance, a system may include an optical source configured to generate a beam of light. The system may include at least one modulator configured to encode data on the beam of light to produce an encoded beam of light/encoded plurality of pulses. The system may include a spectrally-equalizing amplifier configured to receive the encoded beam of light/encoded plurality of pulses from the at least one modulator and both amplify and filter the encoded beam of light/encoded plurality of pulses to produce a filtered beam of light/filtered plurality of pulses, thereby spectrally equalizing a gain applied to the encoded beam of light. In some cases, the system may slice the beam of slight, to ensure a detector has impulsive detection. In some cases, the system may include a temperature controller to shift a distribution curve of wavelengths of the optical source.

Abstract: An optical wireless communication system and method An optical wireless communication (OWC) system comprises: a multiple input multiple output (MIMO) device configured to provide a plurality of signals each representing a respective data stream; conditioning circuitry configured to receive the plurality of signals from the MIMO device and process the plurality of signals to produce at least one conditioned signal representative of the data stream(s) and suitable for transmission using an OWC transmission device; an OWC transmission device comprising at least one transmitter for transmitting light and configured to be responsive to the at least one conditioned signal to transmit light representative of the data stream(s) using the at least one transmitter.

Abstract: Consistent with an aspect of the present disclosure, electrical signals or digital subcarriers are generated in a DSP based on independent input data streams. Drive signals are generated based on the digital subcarriers, and such drive signals are applied to an optical modulator, including, for example, a Mach-Zehnder modulator. The optical modulator modulates light output from a laser based on the drive signals to supply optical subcarriers corresponding to the digital subcarriers. These optical subcarriers may be received by optical receivers provided at different locations in an optical communications network, where the optical subcarrier may be processed, and the input data stream associated with such optical subcarrier is output. Accordingly, instead of providing multiple lasers and modulators, for example, data is carried by individual subcarriers output from an optical source including one laser and modulator. Thus, a cost associated with the network may be reduced.

Abstract: An optical signal transmission method according to an embodiment of the disclosure is an optical signal transmission method in which a processor performs at least part of each operation, and may include an operation of receiving a data stream, an operation of separating at least part of the data stream into three channels, modulating the separated data streams respectively according to M-ary frequency shift keying (M-FSK) scheme so as to produce an FSK modulated signal, an operation of combining a plurality of FSK modulated signals modulated respectively in the three channels, and producing a color modulated signal according to a bit-color mapping table set in advance, and an operation of transmitting the color modulated signal by controlling a light source of the same optical channel based on the color modulated signal.

Abstract: An ONU includes a communication unit, an abnormal light emission prevention unit, and a control unit that transmits a data signal and a transmission permission signal to the communication unit and transmits the transmission permission signal to the abnormal light emission prevention unit between a transmission start time and a transmission end time. When the transmission permission signal is received, the communication unit, transmits an optical signal to an OLT, and transmits an operation signal to the abnormal light emission prevention unit during the transmission of the optical signal. The abnormal light emission prevention unit transmits a stop signal to the communication unit when a difference between a time for which the transmission permission signal is received and a time for which the operation signal is received is greater than or equal to a threshold value. The communication unit stops when the stop signal is received.

Abstract: A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

Abstract: Coherent optical communications technology for recovery of 1D and 2D formatted optical signals. For example, 1D or 2D formatted signals that travel through fiber optic media may be recovered by separating the light into X- and Y-polarization components, rotating one polarization component (e.g., Y-component) into the polarization space of the other component (e.g., Y-component into the X-polarization space), delaying the rotated component enough to avoid destructive interference and combining the delayed component with the undelayed component to form a folded optical signal, which may then be processed as a X-polarized signal.

Abstract: Devices, methods and systems for generating wideband, high-fidelity arbitrary radio frequency (RF) passband signals are described. A voltage tunable optical filter for arbitrary RF passband signal generation includes a first input configured to receive a broadband optical pulse train, a second input configured to receive a first control voltage representative of an amplitude signal, an electrooptic modulator to receive the broadband optical pulse train and the first control voltage, to modulate the broadband optical pulse train in accordance with the amplitude signal, and to produce two complementary optical outputs that form two arms of an interferometer, an optical delay component to impart an optical path difference into one of the complementary outputs of the electrooptic modulator, and a combiner or a splitter to receive two complementary optical outputs of the electrooptic modulator after impartation of the optical path difference and to produce an output interference pattern of fringes.

Abstract: An optical wireless transmission device according to an embodiment of the present invention comprises: a modulation unit for receiving input of a first input signal and outputting a first output signal; and a light source control unit for controlling a first light source in accordance with the first output signal. The first output signal repeats “0” and “1” in a first phase during clock time if a binary value of the first input signal is 0, and repeats “0” and “1” in a phase opposite from the first phase during the clock time if a binary value of the first input signal is 1.

Abstract: Described herein are optical sensing devices for photonic integrated circuits (PICs). A PIC may comprise a plurality of waveguides formed in a silicon on insulator (SOI) substrate, and a plurality of heterogeneous lasers, each laser formed from a silicon material of the SOI substrate and to emit an output wavelength comprising an infrared wavelength. Each of these lasers may comprise a resonant cavity included in one of the plurality of waveguides, and a gain material comprising a non-silicon material and adiabatically coupled to the respective waveguide. A light directing element may direct outputs of the plurality of heterogeneous lasers from the PIC towards an object, and one or more detectors may detect light from the plurality of heterogeneous lasers reflected from or transmitted through the object.

Abstract: An example system includes a first network device having first circuitry. The first network device is configured to perform operations including receiving data to be transmitted to a second network device over an optical communications network, and transmitting first information and second information to the second device. The first information is indicative of the data, and is transmitted using a first communications link of the optical communications network and using a first subset of optical subcarriers. The second information is indicative of the data, and is transmitted using a second communications link of the optical communications network and using a second subset of optical subcarriers. The first subset of optical subcarriers is different from the second subset of optical subcarriers.

Abstract: An optical network component and method are herein described. The system and method include determining a first power of an optical modulator using a first photodetector and a second power of the transmitter using a second photodetector, determining a contrast ratio based on the first power and the second power, and determining a modulation loss based on the contrast ratio.

Abstract: Reflection between a Mach-Zehnder modulator and a termination resistor is suppressed. An optical modulator includes a differential drive open collector driver IC, a differential drive semiconductor Mach-Zehnder modulator, and a differential terminator. The Mach-Zehnder modulator includes waveguides and a differential high-frequency line. The differential terminator includes a differential high-frequency line and termination resistors. The differential high-frequency line includes a capacity provided at least one of between signal lines and between a signal line and a ground line.

Abstract: Cost-effective high-data-rate optical data transceivers are presented, comprising an electronic analog transversal filter simultaneously providing one or more of bandwidth compensation and forward impairment compensations for the transmitted optical signal.

Abstract: A system comprises quantum control interconnect circuitry configured to receive a plurality of fixed-frequency signals, a variable-frequency signal, a quantum control pulse, a quantum element readout pulse, and a quantum element return pulse. The circuitry is operable to upconvert the quantum control pulse using the fixed-frequency signals. The circuitry is operable to upconvert the readout pulse using the variable-frequency signal. The circuitry is operable to downconvert the return pulse using the variable-frequency signal.

Abstract: A hyperspectral radiometer may comprise one or more antennas, a electro-optical modulator modulating the received RF signal onto an optical carrier to generate a modulated signal having at least one sideband; a filter filtering the modulated signal to pass the sideband to a photodetector; and a photodetector producing an electrical signal from which information of the RF signal can be extracted. In some examples, the optical sideband may be spatially dispersed to provide a plurality of spatially separate optical components to the photodetector, where the spatially separate optical components having different frequencies and correspond to different frequencies of the received RF signal. In some examples, the passed sideband may be mixed with an optical beam having a frequency offset from the optical carrier to form a combined beam having at least one optical signal component having a beat frequency from which information of the RF signal can be extracted.

Abstract: An initial change and a secular change in an optical characteristic and a high frequency characteristic in a case where an optical modulator is mounted in a package of an optical transmission apparatus are suppressed while improving a space utilization rate in the package of the optical transmission apparatus. An optical modulator that is electrically connected to an electric circuit configured on a circuit board, includes: a package that houses an optical modulation element; and a signal input part or the like for inputting an electric signal for causing the optical modulation element to perform an modulation operation from the electric circuit, in which the package has, on a part of a bottom surface facing the circuit board, a first protrusion portion protruding from the bottom surface, and the signal input part is provided on an upper surface of the first protrusion portion.

Abstract: Systems, methods, and devices are disclosed for implementing photonic links. Methods include transmitting light using an optical emitter, splitting, using an input coupler, the light into a first path and a second path, the first path being provided to a modulator, and the second path being provided to a phase shifter, and combining, using an output coupler, an output of the modulator and an output of the phase shifter. Methods further include identifying a modulator phase angle that reduces a third order distortion at an output of the output coupler, applying a first bias voltage to a modulator to maintain the identified modulator phase angle, and applying a control signal to the phase shifter to maintain a phase difference between an output of the modulator and an output of a phase shifter.

Abstract: A high average and peak power single transverse mode laser system is operative to output ultrashort single mode (SM) pulses in femtosecond-, picosecond- or nanosecond-pulse duration range at a kW to MW peak power level. The disclosed system deploys master oscillator power amplifier configuration (MOPA) including a SM fiber seed, outputting a pulsed signal beam at or near 1030 nm wavelength, and a Yb crystal booster. The booster is end-pumped by a pump beam output from a SM or low-mode CW fiber laser at a pump wavelength in a 1000-1020 nm wavelength range so that the signal and pump wavelengths are selected to have an ultra-low-quantum defect of less than 3%.

Abstract: A photonic processor includes a modulator, an optical filter, and a polarization combiner. The modulator is configured to receive an electronic signal, first optical control signal, and first optical operating signal, the first optical operating signal received from an optical source circuit on a first path having a first length, the first optical control signal received from an optical control circuit on the first path; modulate the first optical operating signal using the electronic signal to provide an intensity-modulated optical operating signal comprising a first optical operating carrier, first sideband, and second sideband; and modulate the first optical control signal using the electronic signal to provide an intensity-modulated control signal comprising a first optical control carrier. The optical filter is configured to extract the first optical operating carrier and first sideband from the intensity-modulated optical operating signal and provide the second sideband and the control carrier.

Abstract: Described herein are optical sensing devices for photonic integrated circuits (PICs). A PIC may comprise a plurality of waveguides formed in a silicon on insulator (SOI) substrate, and a plurality of heterogeneous lasers, each laser formed from a silicon material of the SOI substrate and to emit an output wavelength comprising an infrared wavelength. Each of these lasers may comprise a resonant cavity included in one of the plurality of waveguides, and a gain material comprising a non-silicon material and adiabatically coupled to the respective waveguide. A light directing element may direct outputs of the plurality of heterogeneous lasers from the PIC towards an object, and one or more detectors may detect light from the plurality of heterogeneous lasers reflected from or transmitted through the object.

Abstract: Devices, methods and systems for generating wideband, high-fidelity arbitrary radio frequency (RF) passband signals are described. A voltage tunable optical filter for arbitrary RF passband signal generation includes a first input configured to receive a broadband optical pulse train, a second input configured to receive a first control voltage representative of an amplitude signal, an electrooptic modulator to receive the broadband optical pulse train and the first control voltage, to modulate the broadband optical pulse train in accordance with the amplitude signal, and to produce two complementary optical outputs that form two arms of an interferometer, an optical delay component to impart an optical path difference into one of the complementary outputs of the electrooptic modulator, and a combiner or a splitter to receive two complementary optical outputs of the electrooptic modulator after impartation of the optical path difference and to produce an output interference pattern of fringes.

Abstract: A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.

Abstract: An optical wireless communication system comprising a transmitter apparatus that comprises: an illumination light source configured to output visible light for illumination purposes, and a controller configured to control operation of the illumination light source to produce modulation of the visible light to provide an optical wireless communication signal representing data; a further light source configured to output further light, wherein the controller is configured to control operation of the further light source to produce modulation of the further light to provide a further optical wireless communication signal representing substantially the same data, wherein the visible light and the further light have different wavelengths.

Abstract: A narrow-linewidth tunable external cavity laser includes, sequentially arranged along an optical path, a laser gain chip, a collimating lens, a bandpass filter, a tunable filter, and an output cavity surface. The laser gain chip includes a first end surface and a second end surface positioned along the optical path. The first end surface is further away from the collimating lens and is coated with a highly reflective film to form an external cavity with the output cavity surface.

Abstract: Systems and methods for communicating using both radio frequency (RF) communication and light communication (LC) are disclosed. An example device comprises radio frequency communication circuitry, a light communication transmitter; a light communication receiver; a processor for controlling the device according to executable code; and memory for storing data and executable code, wherein the executable code comprises instructions for causing the processor to establish RF communication with an RF access point using the RF communication circuitry; and to establish LC communication with an LC access point using the LC transmitter, the LC receiver, or both.

Abstract: The disclosure relates to a multi-modulation-format compatible high-speed laser signal generation system and method. The disclosure can greatly improve modulation format compatibility of a laser communication system and saves system upgrading costs and resource costs. The system mainly includes a control instruction unit, a serial-parallel changeover switch unit, a precoding switch unit, a power control unit, an IQ modulator, a narrow line width laser, and a bias point control unit, wherein the control instruction unit is respectively connected to the serial-parallel changeover switch unit, the precoding switch unit, the power control unit, and the bias point control unit; the serial-parallel changeover switch unit, the precoding switch unit, the power control unit, and the IQ modulator are electrically connected in sequence; the narrow line width laser is connected to an optical input end of the IQ modulator; and the bias point control unit is connected to the IQ modulator.

Abstract: A light-transmitting subsystem can include an LED light source including a first to LED light to emit a first wavelength of light with a first center-emission wavelength and a second LED light to emit a second wavelength of light with a second center-emission wavelength that is offset from the first center-emission wavelength. The system can include a first reference oscillator to receive a reference signal from a remote or broadcasting source, and can also include a synchronous modulation and power system to convert the reference signal from a synchronous relative high frequency signal to a synchronous relative low frequency signal and provide synchronized power pulses to the first LED light and the second LED light in synchronous correlation with the synchronous relative low frequency signal to generate a stream of modulated light-signal pulses which includes a first modulated wavelength of light and a second modulated wavelength of light.

Abstract: Systems and methods are disclosed herein for coherently modulating and demodulating coherent optical signals using 5-bit constellations. The 5-bit constellations have improved suitability for short reach optical communications systems. A first 5-bit constellation can be formed from four rings. The first and fourth rings can form quadrature phase-shift keyed four-symbol sub-constellations, and the second and third rings can form phase-shift keyed twelve symbol constellations. Symbols from the third and fourth sub-constellations are arranged to form a square. A second 5-bit constellation can include an inner 16 symbol sub-constellation and an sixteen symbol outer sub-constellation. Each of the symbols of the inner sub-constellation are equally spaced from its nearest neighboring symbols along both the quadrature and in-phase axes. Each of the symbols in the outer constellation has an equal euclidean-distance with its nearest neighboring symbols in the outer sub-constellation.

Abstract: Optical receivers including at least one local oscillator providing local oscillator light at a local oscillator center frequency offset from a received optical signal by a frequency difference. A combiner for combining the optical signal with the local oscillator light and to output at least one combined optical signal. An opto-electrical converter down-converts the combined optical signal into corresponding RF electrical signal at the frequency of the frequency difference. A filter may be provided to at least substantially remove one of the upper and lower electrical signal sidebands to output one of a VSB and SSB RF signal before rectification. A local oscillator frequency controller may adjustably control the local oscillator frequency to provide the difference frequency that produces a specified group delay in the RF electrical signal that may be specified via optical receiver performance parameters and/or user input and offset using a group delay filter.

Abstract: Techniques that facilitate control of dual phase tuners are provided. In one example, a system includes a first phase tuner and a second phase tuner. The first phase tuner is driven to a first phase bias that is different than a desired phase bias for an interferometer. The second phase tuner is driven to a second phase bias. A combination of the first phase bias and the second phase bias corresponds to the desired phase bias.

Abstract: Embodiments of this disclosure provide a method and apparatus for monitoring a modulation depth of a dither signal and an optical transmitter.

Abstract: An indoor visible light positioning method and system based on a single LED lamp. The system includes an LED communication module and a smartphone module. The LED communication module sends its coordinates and shape data to the smartphone module. The smartphone module includes an inertial measurement unit (IMU) and a camera. The IMU is configured to obtain movement data of a smartphone. The camera is configured to shoot video streams of the LED lamp. Computing processing is performed on center point coordinates of the LED lamp and IMU data in the video streams, and constraints are provided by using a homography matrix of ellipses in the video streams, to obtain accurate location information of the smartphone, and provide location-based services such as navigation and query for a user.

Abstract: A method for compensating the distortions introduced by impairments of MZMz implementing an optical transmitter, according to which the level of total amplitude and phase distortions caused by the optical transmitter is measured and all impairments in the constellation domain are compensated by pre-distorting the input signal to be transmitted by symmetrically adding imbalance to the voltage applied to the MZM arms. The imbalance is determined by introducing a phase rotation in either I or in the Q path of the optical transmitter, which compensates the total amplitude distortion, and also introducing a phase rotation to both I and Q paths of the optical transmitter, which compensate the total phase distortion and the phase shift caused by compensating the amplitude distortion, until reaching a desired operating point, which corresponds to the level of pre-distortion.

Abstract: Techniques and mechanisms for exchanging debug information with a repeater and multiplex logic of a platform. In an embodiment, the multiplex logic can be configured to any of multiple modes including a first mode to exchange debug information between the repeater and debug client logic of the platform. Another of the multiple modes may provide an alternate communication path for exchanging functional data, other than any debug information, between the repeater and a physical layer interface of the platform. In another embodiment, the repeater is compatible with a repeater architecture identified by a universal serial bus standard. The physical layer interface is compatible with an interface specification identified by the same universal bus standard.